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Subject[PATCH 1/3] powernv:idle: Use correct IDLE_THREAD_BITS in POWER8/9
Date
From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>

This patch ensures that POWER8 and POWER9 processors use the correct
value of IDLE_THREAD_BITS as POWER8 has 8 threads per core and hence
the IDLE_THREAD_BITS should be 0xFF while POWER9 has only 4 threads
per core and hence the IDLE_THREAD_BITS should be 0xF.

Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/cpuidle.h | 3 ++-
arch/powerpc/kernel/idle_book3s.S | 9 ++++++---
arch/powerpc/platforms/powernv/idle.c | 5 ++++-
3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/cpuidle.h b/arch/powerpc/include/asm/cpuidle.h
index 52586f9..fece6ca 100644
--- a/arch/powerpc/include/asm/cpuidle.h
+++ b/arch/powerpc/include/asm/cpuidle.h
@@ -34,7 +34,8 @@
#define PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT 8
#define PNV_CORE_IDLE_THREAD_WINKLE_BITS 0x0000FF00

-#define PNV_CORE_IDLE_THREAD_BITS 0x000000FF
+#define PNV_CORE_IDLE_4THREAD_BITS 0x0000000F
+#define PNV_CORE_IDLE_8THREAD_BITS 0x000000FF

/*
* ============================ NOTE =================================
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 2b13fe2..9b747e9 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -223,7 +223,7 @@ lwarx_loop1:
add r15,r15,r5 /* Add if winkle */
andc r15,r15,r7 /* Clear thread bit */

- andi. r9,r15,PNV_CORE_IDLE_THREAD_BITS
+ andi. r9,r15,PNV_CORE_IDLE_8THREAD_BITS

/*
* If cr0 = 0, then current thread is the last thread of the core entering
@@ -582,8 +582,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
stwcx. r15,0,r14
bne- 1b
isync
-
- andi. r9,r15,PNV_CORE_IDLE_THREAD_BITS
+BEGIN_FTR_SECTION
+ andi. r9,r15,PNV_CORE_IDLE_4THREAD_BITS
+FTR_SECTION_ELSE
+ andi. r9,r15,PNV_CORE_IDLE_8THREAD_BITS
+ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
cmpwi cr2,r9,0

/*
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 445f30a..d46920b 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -112,7 +112,10 @@ static void pnv_alloc_idle_core_states(void)
size_t paca_ptr_array_size;

core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node);
- *core_idle_state = PNV_CORE_IDLE_THREAD_BITS;
+ if (cpu_has_feature(CPU_FTR_ARCH_300))
+ *core_idle_state = PNV_CORE_IDLE_4THREAD_BITS;
+ else
+ *core_idle_state = PNV_CORE_IDLE_8THREAD_BITS;
paca_ptr_array_size = (threads_per_core *
sizeof(struct paca_struct *));

--
1.9.4
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